The pack at the bottom right of the photo above was a picking error - instead of a pack of two Para PIAT teams I received a late war British Vickers team.
I decided to take a quick pic to compare a figure from each range:
|L to R: Warlord, Foundry, Artizan, 1st Corps|
The Foundry and Artizan figures seem to be a very close match; the Warlord figures are a similar height but less chunky although they won't look out of place mixed in with Artizan and Foundry, unlike the 1st Corps figures. For the 1st Corps packs I've ordered it shouldn't be a complete bust as the prone figures won't look as obviously large and the Jeeps will be OK. As that will give me two usable snipers, two 2" mortar teams and two PIAT teams I won't need to order anything else. OK, maybe some more jeeps.